This invention relates to high wattage incandescent lamps, such as lamps drawing one or several hundred watts, and particularly to a tungsten halogen projection lamp of the C13 type shown in U.S. Pat. No. 3,555,338 which is incorporated herein by reference. The lamp shown therein consists of a continuous coiled filament folded in interconnected vertical segments electrically in series. The vertical filament segments are electrically connected to each other by loops at their upper and lower ends, the loops being formed by apparatus shown in U.S. Pat. Nos. 2,759,498 and 3,163,186. As shown in U.S. Pat. No. 3,555,338, within the lamp envelope upper and lower quartz rods are fused on the two lead wires entering the glass envelope. Also fused in the two quartz rods are hooked wires which engage the upper and lower loops of eight parallel segments of coiled filament and support the eight coil segments between the two quartz rods.
Such a support for the filament segments quite satisfactorily holds the segments in a rectangular array optically centered in front of a reflector. But considerable expense is involved in the complex arrangement of quartz rods and hooked wires, and such lamps are difficult to manufacture.
Accordingly, it is the object of the present invention to provide a way of supporting the coiled filament of a high wattage lamp which simplifies the filament support structure and reduces the cost and difficulty of manufacturing the lamp.